Insulating apparatus for electric fences



L. Jgs LING 2,311,779 INSULATING APPARATU R ELECTRIC FENCES Filed Aug. 22, 1940 2 Sheets-Sheet l B I (Q g) Feb, 23, 1943.

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INSULATING APPARATUS FOR ELECTRIC FENCES Filed Aug. 22, 1 940 Z'ShGGTS-SI'IGML 2 b W N W "Qatented Feb. 23, 1943 UNITED STATES PATENT OFFICE INSULATING APPARATUS FOR ELECTRIC FENCES Lorell John Schilling, Brookfield, 111., assignor to Babson Bros. Co., a corporation of Illinois Application August 22, 1940, Serial No. 353,729

4 Claims. (Cl. 174-194) This invention relates to insulating apparatus for electric fences, and more particularly to improved insulators and supporting means therefor.

One feature of this invention is that it provides improved means for supporting the wire of an electric fence; another feature of this invention is that it provides an improved line insulator for such a fence, having better water dispersing properties and less likelihood of breakage; another feature of this invention is that an improved strain insulator is provided; a further ieaone is that improved mounting bracket means improved means of attaching the insulators to such brackets are here disclosed; other features and advantages of this invention will be apparent from the following specification and the drawings,

which:

Figure 1 is a side view of a line insulator and mounting bracket in place on a wooden post; Figure 2 is a front elevation oi the structure shown in Figure 1; Figure B is a sectional View along the line 3 of figure 2: Figure 4 is a sectional view along the line 4 of Figure 1; Figure 5 is a perspective View of a mounting bracket and tube for a line insulator; Figure 6 is a top view of a line insulator and bracket wired to a metal fence post:

*cking current of high voltage and low amper- When an animal contacts the fence the ciris completed to ground and the animal re a shock. causing it to shy away from the 2. After several such experiences the animals rest that they normally can be used with light r-vi t movement particu" c nnection with rotation of pa month. where fences are only i. 9. year, the labor costs are greatly i an fence rather than the old- ;d tmze .11 use relying on its strength to in order that these normally stop the animals.

Figure '7 is a view, partly in section, along the open circuit fences shall not be inefficient and waste energizing current it is necessary that they be well insulated from ground. Previous efforts in this direction have involved many disadvantages and defects.

My invention comprises strain and line insulators for electric fences, and mounting means therefor, which are particularly designed for this work. The insulators have less likelihood of breakage than those now in use under the stresses and strains which they encounter in the held; and are particularly designed to disperse water resuiting from rainfall or dew, and to ensure a highly efllcient dielectric condition as soon as possible after a rainstorm or the like. The mounting means are adapted for use on either a wooden or metal post, and are so arranged that they are very easily and quickly assembled with the insulators.

Referring first to the line insulator and its mounting bracket shown in Figures 1 to 5, the insulator i0 is of porcelain or similar conven tional dielectric material. It is generally cylindrical in shape, being provided with certain circumferential grooves and bands which will be described in more detail; and it is carried by bracket H which is in turn mounted upon some supporting means, in these views being shown as nailed to a wooden fence post i2. As may be best seen in Figures 3 and 4, the insulator is has extending substantially into one end thereof an axial slot-like opening adapted to receive a portion of the mounting bracket.

The mounting bracket H, as may be best seen in Figure 5, is formed. of strap metal, a commercial embodiment of this invention being of metal about one-half inch in width and about onesixteenth inch in thickness. The bracket comprises as its principal. parts two portions at right angles to each other, the base portion iii and an extending portion i4 adapted to be received in the opening in the insulator. The other end of the base portion 23 has a turned-up portion i5 provided with a central slot it. The base has a 1 central hole i? therethrough, and the extending portion 5 has a hole "near the base portion hole is near outer end. This latter hole adapted to snugly receive a piece of tum. of resilient material, as synthetic rubber, the tube in a commercial embodiment of this invention being about an inch long.

In use the bracket may be supported wl:-. its base member immediately adjacent a wooden post, for example, by a nail driven through the opening ii. In order to place the insulator onto the supporting bracket it is only necessary to force the opening over the end of the extending portion [4 of the bracket and to push inwardly rather firmly, preferably twisting slightly as this is done. This will cause the rubber tube to deform and stretch, at the same time compacting or lying down along the sides of the extending portion l4, until the insulator can slip down into the position shown in Figure 3. The slot in the base of the insulator is rectilinear, or approximately so. Preferably it has a width just equal to the thickness of the extending portion of the strap metal bracket and a flattened portion of the tubing; and a length several times the diameter of the tubing. This fact, coupled with the preferably slight twisting upon pushing the parts together, results in the portion 14 of the bracket lying diagonally across the slot-like opening, with an end of the piece of tubing in each corner of the opening, as may be best seen in Figure 4. This provides a particularly snug and e iective frictional engagement retaining the insulator in place on the bracket during all normal usage; yet the parts can be disassembled by a quite firm. pull. As is desirable, the stretch ing of the rubber enables the insulator to be forced onto the bracket more easily than it can be pulled off of it.

When the bracket has been nailed or otherwise attached to the post and the insulator placed thereon the fence wire H, which meanwhile may have been strung along the fence line, is laid in the outer groove and fastened in place therein by any convenient means, as by the auxiliary wire 22. This enables very ready and quick setting up of a fence, and tearing it down is equally simple it being only necessary to remove the fence wire and pull the insulator on its supporting brackets. The brackets may be left in place on the post normally, pending the time when these same posts are to be used again.

One of the particular improvements which I am here disclosing is the general shape and configuration of the insulator. As may be best seen in Figures 1 and 3, it has an outer circumfenential wire carrying groove 23; and an additional inner groove 24. The cross section of the outer groove is substantially that of an arc of a circle of greater radius than the depth of the groove; that is, the groove is preferably less than a complete semicircle. Moreover, this redius should be fairly substantial, the groove in a commercial embodiment of this invention being about three-eighths of an inch in length and the radius of curvature being at least one-fourth of an inch. I have found that narrow grooves with a small radius of curvature result in an undesired accumulation of water, and maintain a drop of water in them after a rainfall or heavy dew, rather than draining this water away immediately.

Immediately adjacent the wire-receiving groove and on each side of it are outwardly slopi'ig flat circumferential portions or bands, here identified as 25 and 28. These slope upwardly and outwardly from their point of juncture with will readily drip. I have found that with this particular arrangement of the insulator water in the wire-receiving groove will disperse or spread out over the bands to the outer edges thereof and readily drip therefrom, with. no accumulation of drops of water in the grooves with its resultant loss in insulating emciency.

Another advantage resulting from the relatively shallow grooves with the sloping adjacent bandsis the fact that there are no corners or shoulders against which an angularly disposed wire can get a grip and break the porcelain. Previous insulators, particularly where they are slightly out of line with respect to the direction of the wire, have frequently been broken when the wire was under strain, as from being cold in the winter or from having an animal lean against them heavily.

In order to increase the length of the dielectric path I have not only caused the point of attachment of the insulator to the mounting bracket to be at the center of one end, but I have also provided the additional groove 2% and the skirt-like portion 27. The radius of the arc of the groove 25 is also substantial, the groove merging into the fiat part of the skirt portion and this terminating in a sharp-edged band 28 facilitating drainage.

Turning now more particularly to Figures 6 and 7, it will be seen that this same bracket is particularly adapted for mounting to a light cheap metal fence post not having mounting holes. In the case of use-with a T-shaped metal post of the kind indicated as 36 in Figure 6 the base portion it of the bracket is arranged horizontally, rather than vertically; and it is held in place on the post by a wire, as 3 l, which may be drawn taut by twisting its ends, as at 33. In this case the wire 3i i passed through the hole to and through the central notch IS in the turned-up end portion 95. The result, when the wire is twisted tight, is a triangular supporting arrangement which is particularly effective in mounting the bracket in the desired portion, although quite simple and convenient.

At the ends of the fence wire, or at corners where it changes direction, it is necessary to provide an insulator of a somewhat different type which can take considerable strain. I show such an insulator and its supporting means in Figures 8 and 9. Again the insulator, here indicated as 35, is of generally cylindrical shape; and it is provided with a wire-receiving groove 36 and a pair of immediately adjacent outwardly sloping circumferential bands 3? and 38. The fence wire 35 lies in the groove and would take the position, at a corner of the field, as shown in Figure 9. It can be held in place by any convenient means, as again by the supplementary wire 40; although as long as there is strain on the wire it would remain in position without this holding means.

The supporting bracket is again formed of strap or sheet metal, but in this case is substantially U-shaped. This bracket may be best seen in Figure 8, where it is indicated in general as 55, its two legs being identified as 52 and 43. The leg 62 is received in a slot-like opening and frictionally retained therein by a piece of resilient tubing, in the same manner as described in connection with the other insulators. The other leg at i provided with a mounting point shown as a hole id. In use a wire may be passed through this hole and around a post, the wire 45 being illustrated as passed through the hole, around the wooden post (it, and twisted at G7. The hole 44 is preferably slightly above the center of the groove 36 when the leg 52 is clear into its cooperatingslot-like opening, the center of the hole being about 5% of an inch above the center of the slot in a commercial embodiment of my invention. This arrangement causes the insulator and supporting bracket to assume a position like that illustrated in Figure 8 when there is strain on the fence wire 39. This is particularly desirable in that it causes a component of force tending to keep the insulator 35 in place on the leg 42 of the bracket, these parts being only mounted in the desired relationship by the frictional engagement of the rubber tube with the surfaces of the inside 01' the slotlike opening and with the surfaces of the leg 42 of the bracket.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

1. Apparatus of the character described, ineluding: an insulator having a slot-like opening in one end thereof a mounting bracket having a portion adapted to be received by the opening, said portion having a hole therethrough near its end and transverse to the axis of the opening; and a cylindrical rubber element extending through said hole and adapted to engage the surfaces of the slot-like opening and inserted por tion to i'rictionally maintain said portion in the opening.

2. Apparatus oi. the character described, including: an insulator having an axial slot-like opening in one end thereof; a mounting bracket having a strap portion adapted to be received by the opening, said portion having a hole therethrough near its end; and a rubber tube extending through said hole and adapted to engage the surfaces 01' the slot-like opening and portion to frictionaliy maintain said portion in the opening, the slot-like opening having a width just equal to the thickness of the strap portion and a flattened part of the tube, and a length several times the diameter of the tube, whereby the bracket portion lies diagonally in the slot-like opening.

3. A strap metal bracket for supporting an sulator for an electric fence, comprising a. base portion, a portion extending at right angles from one end thereof for engagement with the insulator, and a. centrally slotted turned-up portion the other end of the base portion, the base por tion having a hole therethrough and the insulator engaging portion having a hole therethrough near the base portion.

4. Apparatus of the character described, in cluding: an insulator having an axial slot-dike opening in one end thereof; a mounting bracket having a strap portion adapted to be received by the opening, said portion having a hole therethrough near its end; and a cylindrical rubber element extending through said hole and adapted to engage the surfaces of the slot=iiiie o in?, and inserted portion to frictionailg said portion in the opening, the slot-hire opening having a width just equal to the thickness of the strap portion and a flattened part oi the element, and a length several times the diameter of the element, whereby the bracket portion has dingonally in the slot-like opening.

LDRELL JOHN 

